This section hasn't really fully evolved yet, but hopefully will be of use to someone
Lie Detector - Pull this one out on your friends!
Light/Dark Indicator - A very simple op-amp comparator circuit
NAND-Based Astable - A very simple astable circuit with timing based around T=RC
Touch Switch - Simple touch switch circuit, works on the fact skin has a resistance
Personal MW Radio - Quite similar to a crystal radio set, but uses a ferrite arial and internal antenna
Simple 5V Power Supply - Stable 5v for ICs from a range of input voltages
More to come soon, maybe...